The present invention generally relates to carton loaders for packaging machines, and in particular, the present invention relates to a system for receiving stacks of cartons and automatically loading the cartons into a position for feeding into a packaging machine for wrapping products with the cartons.
Typically, in the product packaging industry, such as the beverage bottling field, a series of products are passed through a packaging machine wherein groups of products are segmented and wrapped with paperboard cartons. For example, a series of beverage cans can be passed through the packaging machine and wrapped with paperboard cartons in six, eight, or twelve pack configurations. The wrapped products generally then are conveyed further downstream to packaging and palletizing for shipping. Typically, the cartons are preprinted paperboard strips or wraps, generally formed with locking tabs or recesses, and are fed into the packaging machine from a mass feeder. The cartons are fed individually in time with the movement of the products through the packaging machine, so that as the products are segmented into groups, such as six packs, twelve packs, etc., each group is moved in time with a carton that is then placed over and locked about the products.
In the past, the cartons generally have been manually loaded in stacks on the mass feeder for loading into the packaging machine. This generally requires an operator to be present to manually pickup and load stacks of cartons onto the mass feeder for the packaging machine. The machine operator thus generally must continually monitor the level or amount of cartons stacked for loading into the packaging machine so that the stack of cartons waiting to be fed into the packaging machine can be kept relatively constant to ensure the packaging machine will not run out of its supply of cartons during operation. Such a task does not, however, tend to occupy the operator""s time completely, and thus simply having an operator stand by the feeder and periodically load new stacks of cartons onto the feeder for feeding into the packaging machine constitutes an inefficient use of the operator""s time.
Typically, therefore, the operator will be charged with other tasks that they can perform while they periodically check the feeder to load additional stacks of cartons onto the feeder as needed. If, however, the operator fails to keep up with the supply of cartons on the feeder for the packaging machine, the supply of cartons could run out, thus requiring the packaging machine to be shut down and reprimed, resulting in costly downtime and lost production. In addition, many of the operations in a packaging facility are now highly automated, including the packaging of the products within their carton wraps, as well as the depalletizing and transport of stacks of cartons to the packaging machine. It is accordingly desirable to try to further reduce the amount of manual operations required for the operation of the packaging line to the fullest extent possible, to increase efficiency and lower costs, and to try to reduce risks of workplace injuries such as repetitive strain injuries.
It can be seen that a need therefore exists for a carton loading system for automatically loading cartons onto a mass feeder for a packaging machine that solves the above discussed and other related and unrelated problems in the art.
Briefly described, the present invention relates to an automatic carton loader for receiving and loading stacks of cartons onto a mass feeder for feeding into a packaging machine. Carton stacks generally are received in the automatic carton loader from a cross-transfer unit or through a manual loading operation. The automatic carton loader generally includes a loader having a guide assembly including a loading chute defined by a pair of opposed chute members that can be spaced at varying positions with respect to each other to accommodate different sized carton blanks or wraps. The loader further generally includes a stacking platform mounted to a rodless cylinder and moveable between the chute members of the loader to move a stack of cartons received thereon from a receiving or loading position to a loaded position between the chute members.
Keeper plates are positioned between the top ends of the chute members and are connected to a keeper plate cylinder, which causes the keeper plates to be moved between a non-engaging or first position, and an engaging or second position wherein the keeper plates are moved over the stack of cartons loaded between the chute members on the stacker platform. In addition, a carton sensor generally is moved from a first, rest position to a second, detecting position extended between the keeper plates with the movement of the keeper plates into their engaging position. The carton sensor detects and halts the approach of the stack of cartons as the top carton moves into engagement with the keeper plates. As a result, the stack of cartons is captured and held for downward movement into a lowered stacking position for feeding into the product packaging machine.
The loader is pivotally mounted on a carriage that conveys the loader longitudinally along a feeder table of the mass feeder for the packaging machine. A pivot cylinder is connected to the loader for controlling the pivoting of the loader from a substantially vertically oriented loading position to a lowered stacking position for transport along the mass feeder table toward a magazine or supply of previously loaded stacks of cartons accumulated on the mass feeder table for feeding into the packaging machine. The pivot cylinder includes an extensible cylinder rod that is attached at one end to the carriage, and a locking collar preventing the cylinder rod from automatically retracting into the cylinder. Once the loader is reoriented into its stacking position, the loader and carriage are moved along the mass feeder table by a drive system that includes a drive motor that drives a pair of drive belts to which the carriage is mounted.
The loader is moved along the mass feeder table until a trailing edge of the previously loaded supply of cartons on the mass feeder table is detected by a magazine stack approach sensor, which signals the control system of the carton loader to slow the movement of the carriage toward the previously loaded stacks of cartons. A second or magazine stack sensor is positioned slightly downstream from the first or magazine stack approach sensor and detects the trailing edge of the previously loaded stack of cartons, the control system halts further movement of the carriage toward the previously loaded cartons, and the keeper plate cylinder retracts the keeper plates and carton sensor to allow the captured stack of cartons within the loader to be discharged. Thereafter, the carriage is moved rearwardly along the mass feeder table toward a home position, while at the same time, the stacker platform is moved forwardly so as to urge the stack of cartons toward and against the rear of the supply of previously loaded cartons. As the carriage is moved into its home position, its presence is detected by first and second carriage position sensors, which accordingly stop the rearward movement of the carriage, after which the loader is pivoted to its vertically oriented loading position.
Once reoriented into its loading position, the loader is ready to receive additional stacks of cartons therein for stacking into the magazine or supply of cartons for feeding into the product packaging machine. The loading sequence is repeated as needed until a sufficient supply of cartons is provided for supplying to the packaging machine. Thereafter, as the magazine or supply of cartons is depleted as cartons are fed into the packaging machine, the automatic carton loader can be engaged to automatically load additional stacks of cartons to maintain a substantially continuous supply of cartons on the mass feeder.
Various objects, features and advantages of the present invention will become apparent to those skilled in the art upon reading the following detailed description, when taken in conjunction with the accompanying drawings.